Rating gap between blitz and classical, suspicious?

Having a rating gap between your blitz and classical is totally normal on here. The blitz pool is much more competitive. Sadly, not many stronger players are interested in playing slow time controls online. That being said, a 400 point difference is a bigger gap than usual. Maybe blitz chess isn't your thing. Or you just need to play more, get used to the time control, and that rating will rise. Either way, don't worry about it.

Well - I am one of those players who's rating varies quite a bit depending on the type of chess I play. If I were to rate myself, and also use what different sites have rated me.

Blitz: 1400 - 1600
Classical: 1600 - 1800
Postal Chess: 2000 - 2200

The reason for this is simple. I can use opening books in Postal chess. I am also able to move the pieces around on a chess board which make it much easier to spot tactics and positional sacrifices. I'm not sure if this makes a difference for anyone else, but for me, it makes a huge difference in my playing strength.

For whatever reason, blitz chess has never agreed with me, I am just not a fast player and prefer to take my time. I have learned over many years to use blitz as a way to practice my openings and not worry too much about my win-loss percentage or rating.
After a blitz game is over, I simply go back to my opening book to see where I went wrong or where I can improve.

Well, many people play classical control like they play blitz. I think if you use your time that will give you 50-100 points. An additional "cheat" is to draw arrows on the board with the mouse ;-) (I hope this is legal and I didn't just out myself).

its legal

I'm in the same boat with around 2000 classical but only 1550 blitz. (I'm always down on time and also don't take blitz too seriously anymore) I wouldn't worry about others thinking you're a cheater because that happens all the time for worse reasons.

Also I just saw that you've only played around 20 games for each mode. There's a pretty good chance your ratings are a bit off until you've played around 50-100 games for each.

I once saw a guy rated in blitz around 2050 (over 30 rated games, defeated some high rated players) but rated in classical around 1250 (over 200 games). I won against him in an U1500 classical tournament: by time. Is this credible? But I thought: hey, if there would be any suspicious behaviour, the algorithm of lichess would have marked him as a cheater, huh? I just have been too confused to report him, but by this forum thread I remembered the case and looked it up. Both ratings are established.
Edit: Bullet rating around 2200 (more than 200 played games). So to #1: You are not suspicious, but this guy is. :)

Lately , ultrabullet has started. My rating is awful , just 1300. I just cannot play a game in 15 seconds! I wonder how they can do it! My rating gap is huge , but I see no problem!
NEVER PLAY ULTRABULLET WITH A TABLET LOL!

To have a gap between to variants is not suspicius if you ask me, I believe it is normal to do better on a short/long time controll depending on the player you are

since the it different set of people playing classical and blitz there is no reason to assume that ratings would be the same. Think this way lets all pools have some mean/median rating. This mean rating is about the same as pools start with same values. Now if you have loads of master player and other one does not then the mean would still be same but would mean totally different actual strength.